Indicating instrument



May 28, 1957 T. A. GREEN ETAL INDICATING INSTRUMENT Original Filed July28, 1950 3 Sheets-Sheet l AND May 28, 1957 T. A. GREEN ET AL 2,793,606

INDICATING INSTRUMENT Original Filed July 28, 1950 3 Sheets-Sheet 2 FIG.8

IN V EN TORS THOMAS A. GREEN, F 9 HARVARD H. GORRIEI,

AND JACK F. SHANNON TREVOR FINK May 28, 1957 T. A. GREEN ETAL 2,793,606

INDICATING INSTRUMENT Original Filed July 28, 1950 3 Sheets-Sheet 3INVENTORS THOMAS A. GREEN,

HARVARD H. GORRIE, JACK F. SHANNON TREVOR FINK United States PatentINDICATING INSTRUMENT Thomas A. Green, Willoughby, Harvard H. Gorrie,Cleveland Heights, Jack F. Shannon, Euclid, and Trevor Fink, UniversityHeights, Ohio, assignors to Bailey Meter Company, a corporation ofDelaware Original application July 28, 1950, Serial No. 176,382. andthis application June 10, 1954,-Serial No.

2 Claims. (Cl. 116-1365) Our invention relates to measuring instrumentsand particularly to indicating pressure gages of the vertical edgewiseclass.

The general shape is of a relatively thin rectangle with one end or edgeof the rectangle fittedfor visually observing the indication ofmeasurement by having one or more pointers arranged to move along avertically located scale path. Preferably the unit is mounted with theindicative scale substantially flush with a panel board, the majority ofthe unit projecting behind the panel.

Our unitary construction is not, however, restricted to verticaledgewise panel mounting. One widely accepted usage is for table mountingon bench or console type control panels where the scale edge of the unitis horizontal or at a slight inclination with the horizontal and withmost of the unit projecting beneath the bench or console top.

Furthermore, the unitary enclosed construction allows the gauging-up orstacking of numerous units with the indicative scales parallel orend-to-end. on the other hand, the unit may be incorporated in anassembly of metering or control apparatus to advantage.

While we have chosen to designate our invention as related to pressuregages, we so-narne a general class without meaning to restrict theusefulness of the invention in the measurement of other variablequantities, qualities, conditions positions, or the like. For example,the indicator to be described may provide a visual manifestat ion ofthemagnitude of such variables as fluid rate of fiow,temperature, smokedensity, static pressure, speed, the position of an object; or theinterrelation of measurable values or positions such as a visualcomparison of fluid flow rates, pressures, or the like. Such variables,to be made visually available, may be translated into proportionalpressure values to eifectively actuate our device which may then providean indication in terms of the variable. Furthermore, the indication maybe of a control force or loading value and may constitute the receiverof a fluid pressure telemetering system.

One object of our invention is to provide an indicating pressure gage ofunitary construction adapted for universal mounting or arrangement in'multiple or with other apparatus.

Another object is to provide a miniature type of indicator forminimizing space and weight'requirements in panel board assemblies. 'Q iA further object resides in providing a construction adapted to theready ganging or grouping of a plurality of our indicators.

Another object is to provide an indicating receiver Still other objectswill be apparent from a study of the drawings, the description thereof,and of our claims. In the drawings:

Fig. 1 is a sectional elevation of a single tube gage.

Fig. 2 is a front face view of the assembly of Fig. 1.

Fig. 3 is a view of a portion of the assembly of Fig. 1 taken along theline 33 in the direction of the arrows.

Fig. 4 is an enlarged view of that portion of Fig. l enclosed bydot-dash line and designated 4.

Fig. 5 is an exploded view of a portion of Fig. 1.

Fig. 6' is a view, similar to Fig. l, of a double tube gage. f t

Fig. 7 is a front edge view of the assembly of Fig. 6.

Fig. 8 is a view of a portion of the assembly of Fig. 6, taken along theline 8-8 in the direction of the arrows.

Fig. 9 is a sectionalview of the assembly of Fig. 8 taken along the line99 in the direction of the arrows:

Fig. 10 is a perspective view of a portion of Fig. 6.

Fig. 11 shows a modification of a portion of Fig. 9.

Fig. 12 isan enlarged view of an indicator pointer.

Fig. 13 is a section of the pointer of Fig. 12, along the line 13-13, inthe direction of the arrows.

Fig. 14 is a perspective view of a panel showing mounting possibilitiesof our gage.

Referring now in particular to Fig. l, we show therein a sideelevational view of our preferred apparatus as embodied in what issometimes termed a vertical edgewise indicator. The housing is formed asa die casting obtaining lightness, with rigidity, strength and dusttightness. The shape is in general rectangular with a flat side mountingwall 21, top wall 22, bottom wall 24 and a rear wall 23. The near sideis normally covered by a removable side plate 25 (Fig. '5) which may beheld to the housing 20' by screws threadable into holes 26.- Forpurposes of illustration the housing 20 of Fig. 1 has been sectionedslightly below the ledge (Fig. 5) which provides a resting place for thecover 25.

The housing 20 has no fixed front wall (to the right as viewed inFig. 1) but the opening is desirably closed by a molded transparentwindow 27 which may be of.

glass or a clear plastic. The latter is preferred as less susceptible tobreakage through handling, vibration or shock. The window 27 is formedwitha long radius protrudance to the right (Fig. 1) beyond the limits ofhousing walls 21, 22, 24. The two sides 28 and 29 of window 27 extendrearwardly to join the forward edges of side wall 21 and of cover 25.Along the top a rearward projection 30, and along the bottom a similarprojection 31, enter the confines of the housing as shown.

The projection 31 is provided with a hole 32 which may be adapted toreceive a spring end 33 as shown in Fig.

l or in the dotted position of Fig. 4. In similar manner the upperprojection is provided with a hole receiving a more rigid spring end 34.Figs. 1 and 2 show the window 27 :in its assembled location withprojections. 30 and 31 receiving the ends 33, 34 and thus holding thewindow tightly closing the end opening formed by the housing. 20 andcover 25.

Provision is made for easy assembly as well as for ready removal of thewindow portion 27 for inspection Figs. 1 and 2 i show the window inits;assembled position. Fig. 4 is an and cleaning of the scale, pointer,etc.

enlarged detail of a lower right-hand portion of Fig.1 illustrating theoperation to be performed for removing or inserting window 27.

Refer'ring now particularly to Fig. 4 the dot-dash outline to the leftshows the window structure in the same assembled location as in Fig. 1.If it is desired'to tomove the window structure then a lifting screw 35may be threaded upwardly through the tapped hole 36 of the leaf spring37 until the upper end of screw 35 engages the fixed lowere'nd of rivet38. Continued threadingo'fi screw 35 into hole 36 fiexes the right-handend of spring 37 (around its pivot 39) downwardly thus withdrawing thepin 'end 33 from the hole 32 to a position shown in solid line in Fig.4. i

Such'withdrawal of the pin 33 from the hole 32 allows an operator,through grasping the lower portion of window 27, to move the lowermostprojection 31 outwardly from the wall 24 until the pin 34 no longerengages the upper projection 38 and the window 27 is'cornpletelyremoved. It may be reinserted through a reverse operation of firstengaging the hole in upper projection 30 with the pin 34 and thensliding the lower portion of the Window inwardly until it completelycloses the end cavity of the assembly. Thereafter a backing off of thescrew 35 allows pin 33 to enter the hole 32 and lock the window inplace. The screw 35 may be left partially inserted in the cavity 36 ormay be removed as is shown in Pig. 1. Referring again to Fig. 4 it willbe seen that the rivet 38 serves additionally to hold the scale plateassembly by engaging a projection 40 thereof. The scale plate 41 itselfis'curved to an arc corresponding to the travel of the indicatingpointer and may be the same or slightly different than the outwardsurface are of the window 27. It is only essential to maintainsufficient clearance between the pointer, scale plate 41 and innersurface of window 27 at the mid travel position of the pointer.

The lowermost end of the scale plate 41 receives a rivet 42 holding toit a spring clip 43 effectively spacing the scale plate 41 from theinner lower edge of the window housing. At the upper end of the scaleplate 41 a similar spring clip 44 is provided as well as a projection 45of the scale plate (similar to the projection 40). The pin clip 34 aswell as the projection 45 are held by a rivet 46 to the top wall 22.

' The forwardly arched scale plate 41 is recessed along its edges as at47, 48 providing clearance paths for movable pointers. Centered alongthe arc face of the scale plate 41 is a raised scale portion 49 uponwhich are engra ed or painted the scale graduations. Preferably the sideportions 50, 51 contain information, relative to the scale graduations,of Service which may be flow, pressure, or the like; and of numerals 0,10, 20, etc. relating to the Service and to the scale graduations.

Preferably the pointer end 52 (Fig. 2) travels over the depressedsurface 50 (or 51) with clearance thereover and with its indicating endadjacent to graduations on the elevated portion 49. As viewed in Fig. 1it will be observed that the pointer 52 does not extend'beyond the arcof the surface 49 and does not in any respect overlap the graduations orproduce parallax in reading the gage.

In the present embodiment illumination of the unit is accomplished by arecessed light bulb 53 mounted in top wall 22 behind the window 27 andscale plate 41. A light reflecting surface 54 may comprise a metallic orsimilar plate held in position by the rivet 42. The plate 54 maypreferably be of U-shape having side walls spaced from the side wall 21and the inside of cover 25 to allow pointer travel. This substantiallyprevents 'light from the source 53 entering the housing surroundingshield 54 and minimizing eye viewing of working parts of the instrumentbehind the shield 54 through the slots 47, 48. Normally the scale plate41 may be of some translucent plastic or similar material upon which thegraduations and other indicia are painted or engraved so that they willstand out in contrast to the lighted scale'plate itself when the latteris illuminated by the source 53 and reflection from the surface 54. V s

The light source 53 may be held in a convenient socket assembly 55having terminals 56 and the assembly is removably mounted in a clip 57(Fig. 5) having one or more locking prongs 58 engageable with the innersurface of upper wall 22 of housing 20 through a hole 59. The assemblyis shown in Fig. 1 in its normal operation position wherein the prongs58 are in engagement and one=end of the link 71.

a spring button 60 carried by the clip 57 is thus expanded through ahole 61 in the top of wall 22.

From the assembled position (Fig. 1) the assembly 53, 55, 56, 58, 60cannot be loosened or pulled from the unit, in any direction except thatshown by the arrdw X of Fig. 5. In other words, any strain on 55 or 56,as by wires or conduit, toward the observer of Fig. 1, or away from theobserver, or toward the left, will not cause a pull-out of theassembly-due to the gripping of wedge prongs 58; and those are thenormal directions of undesired strains upon 55, i. e., awayfrom the backof a panel through which the window 27 projects. Desired removal is,however, readily accomplished by pivoting the assembly to ward the rearof the panel in the direction of the arrow X (Fig. 5).

The operative or active element of our improved indicator is illustratedin Fig. 1 as a Bourdon tube 65 having one end permanently fastened to abase casting or forging 66 which is in turn held by screws 67 to theside 21 of the housing 20. All of the contents of the housing 20 aresupported relative to the side plate 21 so that the cover 25 may readilybev removed without disturbing any of the active elements which maycontinue in operation.

The interior of the Bourdon tube 65 communicates with a passage 68 andthe lower wall 24 is provided with a clearance opening 69 to allow pipeconnection to the passage 68. p

The free end of the Bourdon tube 65 is connected through an element 70,connecting link 71 and U-shaped member 72 to angularly position theshaft 73. The shaft 73 is pivotally supported by an assembly heldtogether by'screws 81. One of the plates 81 has an extension 82 throughwhich screws 83 pass into base 66 providing a rigid mounting for theshaft 73. Carried by the shaft 73, in addition to the U-shaped member72, is an enlarged hub 73A and a toothed disc 79. Angular motion of theshaft 73, by the Bourdon tube 65, through the agency of elements 71 and72, angularly moves the elements 73A and 79.

The-pointer arm 74 has a weighted end portion 75. As shown in Fig. 12the pointer arm has a hole 74A clearing the shaft 73. In Fig. 3 thepointer arm 74 and weight 75 are at the right of toothed disc 79 andcarry a bracket 76 which spans the disc 79 to encircle the hub 73A onthe left-hand side of disc 79. The bracket 76 is fastened to the pointerarm 74 by a rivet 76A entering the pointer arm 74 by way of hole 76B.

Carried by the bracket 76, and engaging with the toothed disc 79 is aworm 78 extending in a plane parallel to pointer arm 74. Turning of theworm 78 in the teeth of disc 79 angularly moves the assembly 52, 74, 75,76, 76A, and 78 around the disc 79 and shaft 73. This provides a zero.adjustment for the pointer 52 relative to the scale graduations 49without movement of the shaft 73 or any of the elements which cooperateto angularly position the shaft under the dictates of the Bourdon tube65. The bracket 76, between hub 73A and rivet 76A, locks worm 78 snuglyinto engagement with teeth 79 thereby eliminating error due toclearances required for manufacture and operation.

Carried also by the shaft 73 is one end of a hair spring 85, the otherend being adjustably clamped as at 86 to an extension of a plate 80, fortaking up lost motion of the assembly. V I

As previously mentioned the Bourdon tube 65 angularly positions theshaft 73 through the agencyof an element 70, connecting link-71. andU-shaped member 72. Reference may be had to Fig. 11 which shows thisdriving system to larger scale and additionally shows our improved rangeadjustment.

The member 72 is fastened at one end to the shaft 73 and at its otherend carries an extension having a plurality of range holes90 throughwhich we may selectively pass A screw 91 is threaded through an arm ofthe member 72 and has its end bearing against diameter.

the other arm of the member in a hole or hearing dimple 72A. Adjustmentof the screw 91 serves to position the hole s 90 relative to the pivot73 and to thus vary the dimension A relative to the length B of thepointer arm. Thus the selective holes 90 and the adjusting screw 91provide ameans for varying the ratio of A to B and thus varying therange of pressure which must act upon the Bourdon tube 65 to accomplisha predetermined travel of the pointert52 over the scale 49. Initialadjustment of screw 91 stresses the U member 72 toward an open positionso that the screw is always tightly etfective across the arms of the U.i

Boththe zero' adjusting screw 78 and the range adjust,- ing screw 91 areaccessible through an opening 92 (Fig. I) normally covered by a clip 93held in place ,by the spring plug 94. p

In Fig. ll we show the connecting link 71 formed with a spring-like loopapproximately centered between .the pivot locations 90, 95 and withitscenter of gravity CG normally in line with the pivots 90, 95. The linkis preferably made ,of .020 beryllium copperwire #2 hard and with acomplete loop of approximately V2 in As shown in Fig. 3 the cross-overends at 360 are spacedto prevent rubbing friction.

Shaping the link 71, as shown in Fig. 11, both as a spring-like loop andwith a desired location of the center of gravity, has been found to bethe most desirable constructional arrangement to minimize adverseeffects of vibration, shock, inertia, harmonics, and the like effectsbetween the Bourdon tube and the various elements con nected theretothrough the agency of the link 71. Furthermore, the construction ispreferred where the unit is to be subjected to pitch and roll orswayconditions which accentuate inertia eifects. For some ranges orconditions we may form link 71 as. a straight link or in other desiredconfiguration.

At this point we may observe that the system being described is equallyapplicable to the measurement and indication of either positivepressures or of negative pressures. In the latter case it may bedesirable to turn the unit upside down and reverse the scale which wouldthen he graduated from zero to whatever negative pressure were desiredfor total movement of the pointer 52.

Fig. 10 shows to somewhat enlarged scale the stop system for Bourdontube travel. Fig. 1, having a single Bourdon tube, uses the same generalarrangement. Stop plates 100, 101 are identical and interchangeable. Theplate is provided with a slot 102 and screws 103 adjustably fasteningthe plate to the side 21 of the housing 20. Each of the plates, at itsleading edge, is provided with an upturned stop portion 104. A similarstop portion 105 is staggered somewhat relative to portion 104.

The element 70 is shaped as is shown in Fig. 10 and is reversible andinterchangeable for use on either of two Bourdon tubes. It is ofrelatively stifr material and form and is provided at assembly with aninitial bending to provide the basic Zero adjustment; to take care ofvariations in the length of the Bourdon tube and link and to maintainangularity of arm 74.

As may be seen in Fig. 10 the element 70 has a channel shaped endprojecting as at 106, 107 beyond the cross-section of the Bourdon tube.The central portion of the channel section confines and seals the end ofthe Bourdon tube as well as comprising a solid driving connectionbetween the movable end of the Bourdon tube and the link 71. Consideringthe innermost Bourdon tube (Fig. 10) the extension 107 may travel onlybetween stops 104, 105 which are respectively adjustable by screws 103.On the other hand, the outermost Bourdon tube 65 is limited in thetravel of its free end by extension 107' engaging stops 105, 104'. Thestaggered relation of the spans between these pairs of stops is due tothe fact that the extension 107' travels a different path than theextension 107.

Under, normal assembled operation the extensions 107, 107' may movefreely at small clearance with the inner surface of the side 21 whilethe extensions 106, 106' may move freely at small clearance with theinside of the cover plater25. The extensions 107, 107, 106 and 106'permit however only a relatively small. sideways whip or motion of thefree end of the Bourdon tubes before such motion is stopped byengagement of said extensions with the side wall 21 or with the plate25. At the same time the stops 104, 105', 105, 104 not only limit thetotal travel along ar'cuate paths of the extensions 1'07, 107 but tendto prevent extreme whip or similar motion of the Bourdon tube whichmight otherwise seriously damage the parts drivenpthereby. j I

. Reference may now be had to Fig. 12 which shows to enlarged scale thepointer assembly comprising the pointer arm 74 having at the right-handend the pointer 52. From the pointer, to some location C, the pointerarm 74 is ribbed for strength against whipping and twisting. It issomewhat tapered from the. pointer 52 to location C with the widestportion of the taper near the pointer 52. We have found it quitedesirable to so construct the pointer arm 74 providing progressivelygreater cross-sectional weight away from the pivot hole 74A toward thepointer 52.

Fig. 13 shows a crossesection of the pointer arm 74 at theline 13'16 ofFig. 12 and it will be seen that the arm is bent over to channel shapeat approximately the location C, toward the pivot hole 74A and in factalong both sides of the head of the assembly to some location such asD-D. Adjacent the location D-D a small Weight 75 is fastened to the headof the pointer arm. As previously mentioned the head of the assembly isprovided with a clearance hole 74A which freely encloses a hub of theshaft 73; and is also provided with a hole 76B for. receiving thetrivet76A... We have found that it is desirable to carry the channelcross-sectional shape past these two holes to the left to some locationD D to give transverse strength against shock, whip, and the like andprotect against the possibility of the localized weight 75 bending thehead which is normally of rather thin metal. As mentioned the arm 74 istapered in an increasing direction from near the pivot hole 74Aoutwardly to the pointer 52 with considerable weight moment toward thepointer end as compared to the moment arm of the weight 75. Theincremental weight is low along the pointer arm but the moment is high.The entire pointer structure as shown in Fig. 12 provides what we havefound to be an optimum distribution of weight and rigidityand theassembly of arm 74, weight 75, parts 73, 73A, 78, 79, 76A, 72, and 91 isstatically and dynamically balanced. It has proven completely acceptablefor service: subject to vi-bration, shock, pitch, roll and the likeadverse conditions. The pointer assembly diflers radically from priorconstructions with which we are familiar which usually taper in adecreasing direction toward the pointer end 52.

After the pointer arm assembly is statically and dynamically balanced itis mounted in the unit, and, with the unit in a vertical position (Figs.1 and 2) the pointer will remain in any given position. The hair-spring85 is then given an initial bias such that the pointer 52 rests at itslowermost travel position (opposite zero) which is actually about one p.s. i. above zero pressure (atmospheric) within the Bourdon tube. Underthis bias condition the hair-spring is fastened as at 86 and the link 71should just fit the distance between holes 95-90.

The \Bo-urdon tube elements 65, 70 are not balanced and are subject tovibration, harmonics, etc. On the other hand the pointer assembly isbalanced. It is this balance, plus the loop link 71, which preventsundesired movements of the Bourdon tube end from being transmitted to,and observed at, the pointer 52. The flexing of the loop 71 allows theBourdon tube which is unbalanced to move or vibrate without affectingthe pointer which is balanced.

. 7 r r 1 While we have described in somedetail the structure of Figslin illustration of a single Bourdon tube indicator, we have shown inother figures of the drawing the arrangement of a double pointerindicator whose edge face may be similar to thatshown in Fig.7; Fig. 6shows an inner Bourdon tube 65 in addition to the structure of Fig. l.The general arrangement of driving and adjustment elements is the samefor both Bourdon tube systems and the majority of the parts areinterchangeable or reversible as the case may be. Fig. 10, previouslyreferred to, shows to enlarged view, the stop system for the two tubes.i

Fig. 8 illustrates a combining of-two sets of the parts describedinconnection with Fig. 3, while Fig. 9 shows a section through Fig. 8along the line 9- -4 l't will' be apparent from the study of thesedrawings that theunit is readily adapted to single pointer indication orto double pointer indication and furthermore it will be observed'thatthe Bourdon tubes may be" subjected to either plus 01 minus pressures,it being only necessary to properly arrange the zero location and thescale graduation. Fig. 14 has been added to indicate the versatility oflocation and mounting of our improved indicator upon panel boardstructure. At 1110 we indicate the vertical i 25 edgewise scale mountingof the unit on the vertical front face of a panel 111. At 11-2 themultiple side-by-sidc mounting of a plurality of indicators on the samevertical panel face. At 11-3 the side-by-side gauging, and at 114 theend-to-end gauging, of a plurality of our indicators mounted on thehorizontal or inclined bench board or console surface 115 f a panelstructure. These are indicative only on various mounting arrangements towhich our indicators are adaptable. It emphasizes that the assembly maybe mounted in any plane or direction without alfectingthe normaloperation of the working parts.

This application constitutes a division of our copendingapplication S.N. 176,382, filed July 28, 1950, now abandoned. i i What we claim asnew, and desire to secure by Letter Patentof'thie United States, is:

L 1. A pointer arm assembly for an indicating instrument including; anelongated arm means flat in the plane of angular movement and divided bya pivot near one end into two portions substantially 7 to 1 in length;the long portion'formed to gradually increase in width from ad- Iarranged'between their pointers, a central raised scale portionlengthwise of the plate, and the pointers arranged to describe an arecommon with that of the raised scale portion.

References Cited in the file of this patent.

. UNITED STATES PATENTS 529,435 Weston Nov. 20, 1894 1,824,561 MillerSept. 22, 1931 1,861,255 Arey M-ay'31, 1932 1,913,201 Haven June 6, 19331,979,289 Smith Nov. 6, 1934 2,476,315 Morrison July 19, 1949 2,697,147Harland Dec. 14, 1954 FOREIGN PATENTS 514,790 Great Britain Nov. 17,1939

